BACTERIAL-DEGRADATION OF PYRIDINE, INDOLE, QUINOLINE, AND THEIR DERIVATIVES UNDER DIFFERENT REDOX CONDITIONS

Bacteria have evolved a diverse potential to transform and even minera lize numerous organic compounds of both natural and xenobiotic origin. This article describes the occurrence of N-heteroaromatic compounds a nd presents a review of the bacterial degradation of pyridine and its derivatives, indole, isoquinoline. and quinoline and its derivatives. The bacterial metabolism of these compounds under different redox cond itions - by aerobic, nitrate-reducing sulfate-reducing and methanogeni c bacteria - is discussed. However, in natural habitats, various envir onmental factors. such as sorption phenomena, also influence bacterial conversion processes. Thus, both laboratory and field studies are nec essary to aid our understanding of biodegradation in natural ecosystem s and assist the development of strategies for bioremediation of pollu ted sites. Occurring predominantly near (former) wood-treatment facili ties, creosote is a frequent contaminant of soil, subsoil, groundwater , and aquifer sediments. In situ as well as withdrawal-and-treatment t echniques have been designed to remediate such sites, which are pollut ed with complex mixtures of aromatic and heterocyclic compounds.